Re: Better cardinality estimate when dialing optimizer_features_enable back

  • From: Greg Rahn <greg@xxxxxxxxxxxxxxxxxx>
  • To: nkodner@xxxxxxxxx
  • Date: Mon, 23 Nov 2009 16:59:43 -0800

I would second this.  Get a 10053 trace from both versions and look at
the trace file in your favorite graphical diff tool.  Look for the
cardinality/density calculation.  I would do this for the full query
as well as your one table test case .

What are the two execution plans of the full query?

On Mon, Nov 23, 2009 at 3:55 PM, Stefan Knecht <knecht.stefan@xxxxxxxxx> wrote:
> Just a quick thought...
>
> One thing you can try is to take a 10053 trace, and check for the values of
> the various underscore (optimizer features), as well as bugfixes listed in
> the tracefile, for both values for optimizer_features_enable. Any difference
> you may spot may lead you to some more information.

-- 
Regards,
Greg Rahn
http://structureddata.org
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